MB and myocardial infarction: Interestingly, we have shown previously that oxidized myoglobin is present in the damaged myocardium after experimental heart attack in rats, however, no evidence of 3-chlorotyrosine was detected in gel purified rat heart Mb [30], which is completely consistent with the majority of HOCl oxidation of Mb yielding serial addition of molecular oxygen at redox active amino acids rather than producing detectable tyrosine chlorination.